Guidewire position locators are useful for detecting and locating the position of a workpiece during manufacturing operations. Centerless grinders are manufacturing machine tools that can be used to grind elongate cylindrical workpieces such as wires, rods, pins, golf club shafts and the like. In order to meet the high demand for precision grinding operations, centerless grinder assemblies have been enhanced in recent years to include computer controlled guidewire position locators. For example, high quality systems are disclosed in U.S. Pat. Nos. 5,746,644 and 5,674,106, that are assigned to the same assignee as the present invention, Royal Master Grinders, Inc. of Oakland, N.J.
In order to understand why it is desirable to incorporate a guidewire position locator as part of a centerless grinder assembly, it is useful to be somewhat familiar with centerless grinder assemblies generally. A brief description of the process of using a centerless grinder as well as the structure and operation of traditional components of centerless grinders now follows.
The process of using a centerless grinder to machine elongate cylindrical workpieces is also known as grinding the workpieces or removing stock from the workpieces in order to obtain the desired configuration. Centerless grinders are particularly useful where precision tolerances are required and where accurate profiles are desirable. Guidewire position locators facilitate the manufacture of workpieces under such conditions.
Centerless grinders include three main components. A work wheel, which is also known in the art as a grinding wheel, a regulating wheel and a work rest blade. The work wheel is the machine component that usually performs the actual removal of stock from the workpiece. The work wheel thus determines the surface finish and the overall configuration of the workpiece. The surface texture of the work wheel can be varied depending upon the particular grinding operation desired.
The regulating wheel is the machine component that directs and guides the workpiece to the work wheel. The regulating wheel is also responsible, in combination with the work wheel, for driving the workpiece and causing it to rotate during the grinding process.
The work rest blade is the machine component that provides support for the workpiece during machining (i.e., grinding) operations. The regulating wheel will cause the workpiece to rotate on the work rest blade while the work wheel removes the amount of stock required to obtain the desired diameter or taper of the associated workpiece. Prior art work rest blades include horizontal or angled support surfaces. The particular orientation of the work rest blade surface may be selected in accordance with the required configuration of the completed workpiece.
Royal Master Grinders, Inc. of Oakland, N.J. developed a centerless grinder having a guidewire position locator including individual photoelectric sensors that detect the position of the trailing end of the workpiece during machining operations. The detected signal is processed and causes the regulating wheel to change its position with respect to the work wheel so that the configuration of the workpiece is modified. As the trailing end of the workpiece is detected by additional sensors, further signals are generated and processed which may cause the regulating wheel to again change its position with respect to the work wheel. Accordingly, the machined workpiece may include one or more tapered sections. The tapered sections may be gradual, or abrupt, depending upon the desired configuration of the workpiece. Royal Master's aforementioned prior art centerless grinder is widely used in commercial practice.
The individual optical sensing elements of Royal Master's prior art centerless grinder are spaced from each other at about 1/2 inch intervals. Each of the optical sensing elements include an optical fiber that has the diameter of about 0.05 inch. The position locator system incorporated into Royal Master's prior art centerless grinder assembly is thus physically limited by the distance between the fiber optic sensing elements. Although Royal Master's centerless grinder is believed to be highly accurate in manufacturing workpieces that require precise dimensions and tapers, a need continues to exist to improve the accuracy.
A modified embodiment of the aforementioned centerless grinder includes independently adjustable individual sensors which can be arranged at a desired position with respect to the workpiece. Such independently adjustable individual sensors may require various adjustments in order to set the parameters of the associated centerless grinder machine to perform grinding operations that are sufficient to produce a workpiece having a customized configuration.
A need continues to exist in prior art centerless grinders to more accurately detect the position of the elongate workpiece during machining operations and to transmit detected data about the position of the elongate workpiece to an associated computer system so that any required adjustments can be made to assure that the workpiece is manufactured in accordance with required precise dimensions.
Notwithstanding the sophisticated and high quality systems developed by Royal Master Grinders, and other systems that may use various embodiments of optical guidewire position locators, a substantial need exists for an improved guidewire position locator, particularly for use with centerless grinders.